Re: UV filter or software correction or wp editing
Re: UV filter or software correction or wp editing
- Subject: Re: UV filter or software correction or wp editing
- From: Graeme Gill <email@hidden>
- Date: Wed, 26 Apr 2006 12:12:25 +1000
Roberto Michelena wrote:
2) try to 'fill in' the missing spectral values for ProfileMaker to
accept the data as spectral, and use the brightener correction in
software.
It is normal practice to do this. From CIE Colormetry, Second Edition,
Section 3.2, The use of abridged or truncated data:
"In practical applications, all the required data may not be available
because of abridgement or truncation. Many times it is possible
to predict the needed but unmeasured data. It is recognized that
calculation from predicted, rather than from measured data, or
from abridged or truncated data, may be inexact, but the investigator
can often be satisfied that the accuracy is sufficient for the
intended use of the tristimulus values."
Note that most of the data is already abridges - it's only
at 10nm intervals, and it's often truncated, since the
CIE recommends using the range 380 to 780 nm for summation.
If extrapolation is to be used to fill in the truncated
values, the CIE recommend ".. in the absence of other information,
unmeasured values (...) may as a rough approximation be set equal
to the nearest measured values ..."
Of course you a free to use other extrapolation methods, if
you think they will be more accurate.
Graeme Gill.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden